ROCK CREEK WATERSHED RESTORATION PLAN TROUT UNLIMITED March 2018 Acknowledgements Rob Roberts and Christine Brissette of Trout Unlimited provided project management for the development of this report. TU would also like to thank Elizabeth Mohr, Tess Scanlon, and Max Lewis for their work and dedication to this project. In addition, the following entities contributed time and effort to this document and the restoration planning therein: • Beaverhead Deerlodge National Forest • Five Valleys Land Trust • Granite County • Granite Conservation District • Granite Headwaters Watershed Group • Lolo National Forest • Montana Department of Environmental Quality • Montana Fish, Wildlife and Parks • Natural Resource Conservation Service • Powell County • Residents of Rock Creek, public meeting participants and survey participants • Soil and Water Conservation Districts of Montana • United States Bureau of Land Management • United States Environmental Protection Agency • United States Fish & Wildlife Service Table of Contents Acknowledgements .................................................................................................................................................. 2 1.0 Introduction ....................................................................................................................................................... 1 1.1 Plan Organization .............................................................................................................................. 1 1.2 A Historical Note................................................................................................................................ 1 1.3 Key Information Sources ................................................................................................................... 2 2.0 Watershed Characteristics ................................................................................................................................. 4 2.1 Geography ......................................................................................................................................... 4 2.2 Climate .............................................................................................................................................. 4 2.3 Geology and Soils .............................................................................................................................. 5 2.4 Land Ownership ................................................................................................................................. 6 2.5 Land Cover ......................................................................................................................................... 6 2.6 Wilderness and Roadless Areas ......................................................................................................... 8 2.7 Recreational Areas ............................................................................................................................ 8 2.8 Transportation Networks .................................................................................................................. 8 3.0 Natural Resources and Resource Use ................................................................................................................ 9 3.1 Agriculture ......................................................................................................................................... 9 3.2 Mining................................................................................................................................................ 9 3.3 Timber ............................................................................................................................................... 9 3.4 Water Supply ................................................................................................................................... 11 3.41 Surface Water ......................................................................................................................... 11 4.42 Groundwater........................................................................................................................... 12 3.43 Water rights ............................................................................................................................ 13 3.431 East Fork Rock Creek Dam .................................................................................................... 14 3.5 Fish .................................................................................................................................................. 15 3.51 Bull Trout ................................................................................................................................ 15 3.52 Westslope Cutthroat Trout ..................................................................................................... 16 3.53 Sport Fish ................................................................................................................................ 16 3.6 Wetlands ......................................................................................................................................... 16 3.7 Terrestrial Habitat ........................................................................................................................... 19 4.0 Watershed Condition: Causes and Sources of Impairment ............................................................................. 22 4.1 Sediment ......................................................................................................................................... 22 4.11 Effects of Sediment on Beneficial Uses .................................................................................. 22 4.12 Sediment Impairments, Sources, and TMDL .......................................................................... 22 4.2 Nutrients .......................................................................................................................................... 23 4.21 Effects of Excess Nutrients on Beneficial Uses ....................................................................... 23 4.22 Nutrient Impairments, Sources, and TMDL ............................................................................ 23 4.3 Metals .............................................................................................................................................. 25 4.31 Effects of Elevated Levels on Beneficial Uses ......................................................................... 25 4.32 Metals Impairments, Sources, and TMDLs ............................................................................. 25 4.4 Temperature .................................................................................................................................... 27 4.41 Temperature and Aquatic Life ................................................................................................ 27 4.42 Temperature Impairments, Sources, and TMDL ..................................................................... 28 5.43 Stream Temperature and Climate Change ............................................................................. 29 4.5 Streamflow Depletion ..................................................................................................................... 29 4.51 Stream Segments of Concern ................................................................................................. 29 4.52 Streamflow and Climate Change ............................................................................................ 29 4.6 Geomorphological changes ............................................................................................................. 29 4.7 Fish Passage and Entrainment ........................................................................................................ 30 4.71 Culverts ................................................................................................................................... 30 4.72 Irrigation Diversions ................................................................................................................ 30 4.8 Vegetation ....................................................................................................................................... 31 4.81 Riparian Vegetation Alteration ............................................................................................... 31 4.82 Weeds ..................................................................................................................................... 31 4.9 Point Source Pollution ..................................................................................................................... 31 5.0 Information Gaps ............................................................................................................................................. 33 6.0 Watershed Restoration: The Path to Improvement ........................................................................................ 33 6.1 Management Goals and Objectives ................................................................................................ 33 6.2 Management Actions and Restoration Opportunities .................................................................... 37 6.21 Landowner outreach ............................................................................................................... 37 6 .22